video-shader-toys/apps/LoopThroughWithOpenGLCompositing/gl/RenderEngine.h

#pragma once

#include "OpenGLRenderPass.h"
#include "OpenGLRenderPipeline.h"
#include "OpenGLRenderer.h"
#include "OpenGLShaderPrograms.h"
#include "HealthTelemetry.h"
#include "RuntimeSnapshotProvider.h"

#include <windows.h>

#include <cstdint>
#include <chrono>
#include <functional>
#include <map>
#include <string>
#include <vector>

class RenderEngine
{
public:
	using RenderEffectCallback = std::function<void()>;
	using ScreenshotCallback = std::function<void()>;
	using PreviewPaintCallback = std::function<void()>;

	struct OscOverlayUpdate
	{
		std::string routeKey;
		std::string layerKey;
		std::string parameterKey;
		JsonValue targetValue;
	};

	struct OscOverlayCommitCompletion
	{
		std::string routeKey;
		uint64_t generation = 0;
	};

	struct OscOverlayCommitRequest
	{
		std::string routeKey;
		std::string layerKey;
		std::string parameterKey;
		JsonValue value;
		uint64_t generation = 0;
	};

	RenderEngine(
		RuntimeSnapshotProvider& runtimeSnapshotProvider,
		HealthTelemetry& healthTelemetry,
		CRITICAL_SECTION& mutex,
		HDC hdc,
		HGLRC hglrc,
		RenderEffectCallback renderEffect,
		ScreenshotCallback screenshotReady,
		PreviewPaintCallback previewPaint);
	~RenderEngine();

	bool CompileDecodeShader(int errorMessageSize, char* errorMessage);
	bool CompileOutputPackShader(int errorMessageSize, char* errorMessage);
	bool InitializeResources(
		unsigned inputFrameWidth,
		unsigned inputFrameHeight,
		unsigned captureTextureWidth,
		unsigned outputFrameWidth,
		unsigned outputFrameHeight,
		unsigned outputPackTextureWidth,
		std::string& error);
	bool CompileLayerPrograms(unsigned inputFrameWidth, unsigned inputFrameHeight, int errorMessageSize, char* errorMessage);
	bool CommitPreparedLayerPrograms(const PreparedShaderBuild& preparedBuild, unsigned inputFrameWidth, unsigned inputFrameHeight, int errorMessageSize, char* errorMessage);
	bool ApplyPreparedShaderBuild(
		const PreparedShaderBuild& preparedBuild,
		unsigned inputFrameWidth,
		unsigned inputFrameHeight,
		bool preserveFeedbackState,
		int errorMessageSize,
		char* errorMessage);

	const std::vector<RuntimeRenderState>& CommittedLayerStates() const;
	void ResetTemporalHistoryState();
	void ResetShaderFeedbackState();
	void ClearOscOverlayState();
	void UpdateOscOverlayState(
		const std::vector<OscOverlayUpdate>& updates,
		const std::vector<OscOverlayCommitCompletion>& completedCommits);
	void ResizeView(int width, int height);
	bool TryPresentPreview(bool force, unsigned previewFps, unsigned outputFrameWidth, unsigned outputFrameHeight);
	bool TryUploadInputFrame(const VideoIOFrame& inputFrame, const VideoIOState& videoState);
	bool RenderOutputFrame(const RenderPipelineFrameContext& context, VideoIOOutputFrame& outputFrame);
	bool ResolveRenderLayerStates(
		bool useCommittedLayerStates,
		unsigned renderWidth,
		unsigned renderHeight,
		double oscSmoothing,
		std::vector<OscOverlayCommitRequest>* commitRequests,
		std::vector<RuntimeRenderState>& layerStates);
	void RenderLayerStack(
		bool hasInputSource,
		const std::vector<RuntimeRenderState>& layerStates,
		unsigned inputFrameWidth,
		unsigned inputFrameHeight,
		unsigned captureTextureWidth,
		VideoIOPixelFormat inputPixelFormat,
		unsigned historyCap);
	bool ReadOutputFrameRgba(unsigned width, unsigned height, std::vector<unsigned char>& bottomUpPixels);
	bool CaptureOutputFrameRgbaTopDown(unsigned width, unsigned height, std::vector<unsigned char>& topDownPixels);

private:
	OpenGLRenderer mRenderer;
	OpenGLRenderPass mRenderPass;
	OpenGLRenderPipeline mRenderPipeline;
	OpenGLShaderPrograms mShaderPrograms;
	RuntimeSnapshotProvider& mRuntimeSnapshotProvider;
	CRITICAL_SECTION& mMutex;
	HDC mHdc;
	HGLRC mHglrc;

	struct OscOverlayState
	{
		std::string layerKey;
		std::string parameterKey;
		JsonValue targetValue;
		ShaderParameterValue currentValue;
		bool hasCurrentValue = false;
		std::chrono::steady_clock::time_point lastUpdatedTime;
		std::chrono::steady_clock::time_point lastAppliedTime;
		uint64_t generation = 0;
		uint64_t pendingCommitGeneration = 0;
		bool commitQueued = false;
	};

	void ApplyOscOverlays(
		std::vector<RuntimeRenderState>& states,
		bool allowCommit,
		double smoothing,
		std::vector<OscOverlayCommitRequest>* commitRequests);

	std::vector<RuntimeRenderState> mCachedLayerRenderStates;
	uint64_t mCachedRenderStateVersion = 0;
	uint64_t mCachedParameterStateVersion = 0;
	unsigned mCachedRenderStateWidth = 0;
	unsigned mCachedRenderStateHeight = 0;
	std::chrono::steady_clock::time_point mLastPreviewPresentTime;
	std::map<std::string, OscOverlayState> mOscOverlayStates;
};